Toxicological assessment of kretek cigarettes

Eugenol, menthol and other flavour chemicals in kreteks and 'white' cigarettes purchased in Indonesia

BACKGROUND

Flavoured tobacco products are not restricted in Indonesia, a country with about 68 million adults who smoke. Most use clove-mixed tobacco cigarettes ('kreteks'); non-clove ('white') cigarettes are also available. Although the use of flavour chemicals has been identified by WHO as promoting tobacco use, little has been reported for Indonesia about the levels of flavourants in either kreteks or 'white cigarettes'.

METHODS

22 kretek brand variants and nine 'white' cigarette brand variants were purchased in Indonesia during 2021/2022; one of the kretek packs contained three colour-coded variants, giving a total sample number of 24 for the kreteks. Chemical analyses gave the mg/stick (=mg/(filter+rod)) values for 180 individual flavour chemicals that included eugenol (a clove-flavoured compound), four other clove-related compounds and menthol.

RESULTS

Eugenol was present at significant levels in all 24 kreteks (2.8-33.8 mg/stick), but was essentially absent in all of the cigarettes. Menthol was present in 14 of 24 kreteks, with levels ranging from 2.8 to 12.9 mg/stick, and in five of the nine cigarettes, with levels ranging from 3.6 to 10.8 mg/stick. Other flavour chemicals were also found in many of the kretek and cigarette samples.

CONCLUSIONS

In this small sample, we found numerous variations of flavoured tobacco products offered by multinational and national companies in Indonesia. Given the body of evidence that flavours make tobacco products more appealing, regulation of clove-related compounds, menthol and other flavour chemicals should be considered in Indonesia.

Free Radicals in Little Cigar Mainstream Smoke and the Potential Influence of Flavoring Chemicals on Free Radical Production

Implementation of the Tobacco Control Act in 2009 banned characterizing flavors in cigarettes (except menthol and tobacco), but substitution has occurred by the continued availability of alternative flavored products (i.e., flavored little cigars). Little is known about how flavorants in noncigarette tobacco products impact human health. Thus, we investigated the impact of flavorants on free radical production in the mainstream smoke of little cigars. Gas- and particulate-phase free radical yields in mainstream smoke generated from 12 commercial little cigar brands and research little cigars and cigarettes were measured via electron paramagnetic resonance spectroscopy using the International Organization of Standardization (ISO) smoking protocol. Flavorants were extracted from unsmoked little cigars and analyzed by gas chromatography-mass spectroscopy. Gas- and particulate-phase radical yields from little cigars ranged from 13.5 to 97.6 and 0.453-1.175 nmol/unit, respectively. Comparatively, research cigarettes yielded an average of 4.9 nmol gas-phase radicals/unit and 0.292 nmol particulate-phase radicals/unit. From the products, 66 flavorants were identified, with each brand containing 4-24 individual flavorants. The free radical content was strongly correlated with the number of flavorants present in each cigar (r = 0.74, p = 0.01), indicating that highly flavored little cigars may produce higher levels of toxic free radicals. The presence of the flavorant ethyl methylphenylglycidate (strawberry) was associated with >2-fold higher levels of GP radicals (p = 0.001). Our results show that free radical delivery from little cigars is greater than that from research cigarettes and provide empirical evidence for the harmfulness of flavored tobacco products. Additionally, it demonstrates that flavorants present in combustible tobacco products can influence the levels of free radicals produced. Therefore, future tobacco product standards should consider little cigars.

Prevalence and risk factors of oral potentially malignant disorders in Indonesia: a cross-sectional study undertaken in 5 provinces

Detection of subjects with oral potentially malignant disorders in a population is key to early detection of oral cancer (OC) with consequent reduction of cancer-related morbidity and mortality. Our aim was to investigate the prevalence and associated risk factors for OPMD in representative provinces of Indonesia. This cross-sectional study was undertaken in five Indonesian provinces: West Java (WJ), Jakarta (JKT), West Papua (WP), West Kalimantan (WK) and Banda Aceh (BA). Respondents answered a previously validated questionnaire including information on ethnicity, occupation, socioeconomic status (SES), oral health practices, and behaviours associated with oral cancer. An oral examination was undertaken using WHO standardized methodology. Data were analysed using ANOVA, Chi-Square, and logistic regression to assess association between risk factors and mucosal disease. A total of 973 respondents between the ages of 17 and 82 years was enrolled (WJ 35.5%,JKT 13.3% WP 18.3%, WK 9%, BA 23.9%). Tobacco smoking (14.8%), Betel quid (BQ) chewing (12.6%) and alcohol drinking (4%) varied geographically. A well-established OPMD was detected in 137 (14.1%) respondents and 2 (0.2%) presented with chronic ulceration later diagnosed as OC. Leukoplakia was the most common OPMD found (9.7%), while the prevalence of oral submucous fibrosis (OSMF), not previously described in the nation, was 2.3%. Poor knowledge of OC risk factors, poor oral hygiene behaviours, low-income SES and ethnicity were significantly associated with the presence of an OPMD. There is a previously under-reported high prevalence of OPMD in Indonesia. Overall, we found a strong correlation between the presence of an OPMD and individual habituation to known risk factors.

How Do Herbal Cigarettes Compare To Tobacco? A Comprehensive Review of Their Sensory Characters, Phytochemicals, and Functional Properties

Herbal cigarettes, known as tobacco-free or nicotine-free cigarettes, are those recognized as being-tobacco free, being composed of a mixture of various herbs claimed to lessen the smoking habit hazards. However, controversial data regarding its properties occur in the literature with no comprehensive overview or analysis of its effects. Like herbal smokeless tobacco, they are often used to substitute for tobacco products (primarily cigarettes) regarded as a "nonsmoking" aid. This review capitalizes on herbal cigarettes with regard to their quality characteristics, sensory attributes, chemical composition, and health properties to rationalize their choice as a nonsmoking aid. Furthermore, the impacts of heat and/or pyrolysis that occur during smoking on its chemical composition are presented for the first time. Some herbal smokes may produce notable metabolic problems that increase the risk of several chronic metabolic diseases. In general, burning substances from plants can have a variety of negative effects on the body attributed to toxic chemicals such as carbon monoxide, polyaromatics, nicotine, and N-nitrosamines. This review compiles and discusses the phytochemical compositions detected in various herbal cigarettes alongside sensory and quality attributes and health effects.

Uncovering cloves: characterization of volatile compounds present in clove cigarettes

Indonesian clove cigarettes-called "kretek" due to the crackling sound that can be heard when the product burns-are tobacco products containing clove and the "saus", a mixture of essential oils and plant extracts whose ingredients are mostly kept in secret. It is important to determine which ingredients those are to properly assess the effects that clove cigarettes can cause. An organoleptic, qualitative and quantitative analysis was made in 9 different brands of clove cigarettes obtained in Brazil. Nicotine, eugenol, menthol, and β-caryophyllene were quantified through gas chromatography coupled to mass spectrometry. The samples presented 20 different compounds, and all samples had a different combination of the compounds. Nicotine concentrations were generally higher than eugenol, and lower than nicotine concentration in a conventional cigarette. One sample had menthol even though the cigarette pack did not inform that it was a menthol product. There were traces of 2 unusual substances. Clindamycin is an antibiotic that can be used to treat bacterial infections in respiratory airways, and octodrine is an amphetaminic stimulant used in nutritional supplements, considered as a substance of doping by the World Anti-Doping Association. The presence of both substances was not tested using certified reference materials, but its possible presence raises concern about the compounds in kretek cigarettes. There should be more studies about the contents of clove cigarettes, to improve antitobacco legislations and regulations. This way it would be possible to properly inform the risks of smoking clove cigarettes and to diminish the number of tobacco users throughout the world.

Where should I start? A scoping review about the publications on clove cigarettes

INTRODUCTION

The general lack of knowledge about the composition of clove cigarettes and the large number of terms that can be used to define different types of cigarettes that contain cloves makes it difficult to find scientific articles focused on the subject. We reviewed the publications that cited clove cigarettes to assess their relevance.

METHODS

We searched publications on Scopus, ScienceDirect, PubMed, and Portal CAPES during the first semester of 2021, without date restrictions. Through a quality assessment, the studies found were assorted in ten different categories.

RESULTS

Indonesian clove cigarettes-also known as kretek-are a mixture of tobacco and cloves rolled in a cigarette and sprayed with oils, plant extract, and food flavorings, in an unknown quantity and composition, different from each brand, which is usually kept in secret. Due to the relatively low prevalence of use in the general population, most publications on tobacco products tend to ignore clove cigarettes or place them in an existing category. Clove cigarettes can be hand-rolled, machine-made, filtered, unfiltered, and each form can be named differently. The interchangeable use of each term, sometimes grouping conventional cigarettes in the mix, can lead the researcher to consider a publication that should be excluded.

CONCLUSION

The existing regulations on flavored cigarettes, although well-intentioned, are still somewhat vague and broad, leaving possible loopholes that can be exploited by the tobacco industries. Fully understanding the precise effects caused by clove cigarettes can be an important tool in future discussions about tobacco control.

Kretek Cigarettes and Particulate Matter Emissions-An Aerosol Spectrometric Study on Typical Indonesian Brands Flavored With Cloves

INTRODUCTION

In Indonesia, smoking is widespread. The same applies to second-hand smoke (SHS) exposure. More than 90% of Indonesian smokers smoke clove cigarettes, so-called Kreteks. They often contain more tar and nicotine than conventional cigarettes, but little is known about particulate matter (PM) emissions. In smokers' homes, SHS is the main source of PM that is hazardous to health. This study presents data of PM emissions from Kreteks.

METHODS

SHS was generated in a closed 2.88 m³ measuring chamber. PM fractions (PM10, PM2.5, PM1) of three popular Kretek brands (two king-sized and one slim-sized) in comparison to conventional cigarettes and a reference cigarette were measured by laser aerosol spectroscopy in real-time.

RESULTS

The king-sized Kreteks reached PM10 and PM2.5 mean concentrations of up to about 3000 µg/m³, and PM1 mean concentrations of up to about 2700 µg/m³. Consequently, these Kreteks emitted up to about 100% more PM10 and PM2.5, respectively 84% more PM1 than the reference cigarette, and up to about 260% more PM10 and PM2.5, respectively 234% more PM1 than the other investigated cigarettes.

CONCLUSIONS

PM emissions from Kreteks can be very high. The Indonesian public should be informed and warned about it, considering the high prevalence of smoking and SHS exposure, in particular. The Indonesian tobacco control regulation is limited, and it is overdue to start with a serious and effective tobacco control policy. PM declaration to government authorities could be useful in smoking prevention and tobacco control.

IMPLICATIONS

Research data are limited for Kretek cigarettes, including data on particulate matter (PM). The clove buds in Kretek cigarettes are for flavoring the smoke and shall soften the smoke feeling. That makes them very popular in Indonesia, in particular. The declaration of PM data of Kreteks and other tobacco products can play a key role in a more effective tobacco policy to reduce consumption of tobacco products, not only in Indonesia. To provide data on PM emissions, this study ascertained PM amounts in passive smoke from Indonesian Kreteks.

The Discrepancy between Clove and Non-Clove Cigarette Smoke-Promoted Candida albicans Biofilm Formation with Precoating RNA-aptamer

This study explores the influence of precoating aptamer (Ca-apt1) on C. albicans viability while the fungus was growing in the presence of exposing condensed cigarette smoke (CSC), prepared from clove (CCSC) and non-clove (NCSC) cigarettes, for 48 h. Using qPCR, we found that mRNA expression of adhesion-associated genes ( ALS3 and HWP1) was impaired by precoating C. albicans yeast cells with the aptamer. Conversely, the gene transcription was upregulated when aptamer-uncoated yeast was pre-treated with either CSC. In addition, by analysing the result of MTT ([3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] assay, we found that the presence of added CCSC or NCSC in growth medium for 48 h was significantly enhanced C. albicans biofilm development. However, the presence of precoated aptamer was significantly impaired biofilm development accelerated by the NCSC. The inhibitory effect of the Ca-apt1 was not dependent on the precoated aptamer (1ng/μL and 10 ng/μL). Interestingly, we noted that the enhancer effect of treated CCSC was no longer effective when the yeast had been precoated with 10 ng/μL aptamer tested. Additionally, light microscopy analysis revealed that precoating aptamer alleviates morphological changes of C. albicans (from yeast to hypha formation) that are enhanced by adding CCSC or NCSC in the growth medium.

In conclusion, these results suggest that administration on Ca-ap1 exhibits a significant protective effect on CSC-induced biofilm formation by C. albicans.

Level of serum IL-33 and emphysema paraseptal in clove cigarette smoker with spontaneous pneumothorax: A case report

A young male clove cigarette smoker experienced spontaneous pneumothorax and later paraseptal emphysema was detected on high-resolution computed tomography (HRCT) scan without respiratory symptoms. Smoking is a known risk factor for emphysema. Paraseptal emphysema is a type of emphysema that rarely causes respiratory symptoms, nevertheless, usually accompanied by spontaneous pneumothorax. Interleukin 33 (IL-33) is an alarmin cytokine that belongs to the IL-1 family. The effects of IL-33 depend on its structure. In its mature form, it is a cytokine alarmin that binds to ST2 (suppression of tumorigenicity) receptors on the surface of macrophages and innate immune cells to drive Th1/Th2 immune responses, causing oxidative stress, and increased IL-33 production causes polarization of alveolar macrophages to an M2 phenotype. In this study, long-term exposure to clove cigarette smoke caused an increased serum level of IL-33 (43.72 pg/mL) and paucigranulocytic airway inflammation. In paucigranulocytic inflammation, IL-33 is involved in lung parenchymal damage presumably through oxidative stress, activation of alveolar macrophage and increased MMP12 secretion, resulting in alveolar destruction and airspace enlargement.

A Survey of Nicotine Yields in Small Cigar Smoke: Influence of Cigar Design and Smoking Regimens

Introduction

Although the popularity of small cigar brands that resemble cigarettes, including both little cigars (LC) and filtered cigars (FC), has been on the rise, little is known about the delivery of nicotine from these products. Our objective was to determine the nicotine yields of small cigars in comparison to cigarettes.

Methods

Nicotine yields from LC, FC, and 3R4F and 1R6F research cigarettes were determined from mainstream smoke generated on a smoking machine under the International Organization of Standardization (ISO) and Canadian Intense (CI) methods. Market characteristics (price and package label) and physical features (filter ventilation, product weight and filter weight, product length, and diameter) were also determined for eight brands of small cigars.

Results

Nicotine yields in small cigars averaged 1.24 and 3.49 mg/unit on ISO and CI regimens, respectively, compared with 0.73 and 2.35 mg/unit, respectively, for the research cigarettes. Nicotine yields per puff were similar between small cigars and cigarettes. We also found that FC did not differ from LC in nicotine yields. FC and LC differ from each other in many physical design features (unit weight, filter weight, and filter length), but are similar in others (unit length, diameter, and filter ventilation).

Conclusions

Nicotine delivery from small cigars is similar to or greater than that from cigarettes. Thus, for future research and regulatory purposes, standard definitions need to be developed for small cigars, and FC and LC should be evaluated as separate entities.

Implications

Small cigars are similar to cigarettes in their design and use. Although nicotine yields per puff were similar between products, small cigars delivered substantially higher amounts of nicotine per unit than cigarettes. These findings support the growing body of evidence to justify regulating all small cigars, including LC and FC in a similar fashion as cigarettes.

A Cross Sectional Study of Kretek Smoking in Indonesia as a Major Risk to Public Health

BACKGROUND

Tobacco smoking is a major cause of preventable disease and death worldwide. Kreteks are clove-flavored cigarettes made from a combination of tobacco and ground-clove mixed with a sauce, smoked widely in Indonesia. Because health and social consequences of kretek smoking are potentially as great as those of traditional cigarettes, this study examines the prevalence of kretek smoking in Indonesia and associated risk factors.

MATERIALS AND METHODS

The study used nationally representative Indonesia Global Adult Tobacco Survey data. Multiple logistic regression analysis was employed to identify correlates of kretek smoking.

RESULTS

One- third of Indonesian adults smoked tobacco of which about 90.0% smoked kreteks. Prevalence of kretek smoking among men (60.9%) was more than 25 times the rate among women (2.3%). Overall, the highest prevalence of kretek use was in the age group 45-54 years (36.5%), followed by 34-44 (35.1%), 25-34 (34.2 %), and 55-64 years (32.8%). By wealth index, prevalence of kreteks smoking among those in the middle index was almost 50% above the rate for the wealthiest group (36.4% vs 24.8% respectively). Logistic regression results showed that being male, being older, having less education, and being less wealthy were significant predictors of kretek smoking, while urban vs rural residence was not.

CONCLUSIONS

Kretek smoking is common in Indonesia and is entrenched in the sociocultural fabric of the country. However, potential consequences of kretek smoking, particularly as risks for noncommunicable diseases, underscore the importance of a comprehensive approach to tobacco control as outlined in the World Health Organization's MPOWER strategies.

Toxicological assessment of kretek cigarettes: Part 2: kretek and American-blended cigarettes, smoke chemistry and in vitro toxicity

Two commercial kretek cigarettes typical for the Indonesian market and a reference kretek cigarette were compared to the American-blended reference cigarette 2R4F by smoke chemistry characterization and in vitro cytotoxicity and mutagenicity assessments. Despite the widely diverse designs and deliveries of the selected kretek cigarettes, their smoke composition and in vitro toxicity data present a consistent pattern when data were normalized to total particulate matter (TPM) deliveries. This confirms the applicability of the studies' conclusions to a wide range of kretek cigarette products. After normalization to TPM delivery, nicotine smoke yields of kretek cigarettes were 29-46% lower than that of the 2R4F. The yields of other nitrogenous compounds were also much lower, less than would be expected from the mere substitution of one third of the tobacco filler by clove material. Yields of light molecular weight pyrolytic compounds, notably aldehydes and hydrocarbons, were reduced, while yields of polycyclic aromatic hydrocarbons were unchanged and phenol yield was increased. The normalized in vitro toxicity was lowered accordingly, reflecting the yield reductions in gas-phase cytotoxic compounds and some particulate-phase mutagenic compounds. These results do not support a higher toxicity of the smoke of kretek cigarettes compared to American-blended cigarettes.

Toxicological assessment of kretek cigarettes Part 3: kretek and American-blended cigarettes, inhalation toxicity

A typical Indonesian kretek cigarette brand and an experimental kretek reference cigarette were compared to the reference cigarette 2R4F in two 90-day inhalation studies. Male and female rats were exposed nose-only to mainstream smoke for 6 hours daily, for 90 consecutive days. Biological endpoints were assessed according to OECD guideline 413, with special emphasis on respiratory tract histopathology and on lung inflammation (broncho-alveolar lavage fluid levels of neutrophils, macrophages and lymphocytes). Histopathological alterations included: in the nose, hyperplasia and squamous metaplasia of the respiratory epithelium and squamous metaplasia and atrophy of the olfactory epithelium; in the larynx, epithelial squamous metaplasia and hyperplasia; in the lungs, accumulation of macrophages in alveoli and goblet cell hyperplasia in bronchial epithelium. The findings were qualitatively consistent with observations from previous similar studies on conventional cigarettes. Compared to 2R4F cigarette, however, kretek smoke exposure was associated with a pronounced attenuation of pulmonary inflammation and less severe histopathological changes in the respiratory tract. Neutrophilic inflammation was also significantly lower (>70%). These results are consistent with the observations made on smoke chemistry and in vitro toxicology. They do not support any increased toxicity of the smoke of kretek cigarettes compared to conventional American-blended cigarettes.